[4] Van der Voort started a six-year training in internal medicine the following year at the Academic Medical Center and the Onze Lieve Vrouwe Gasthuis (OLVG), both situated in Amsterdam.

[3] He earned a European Diploma in Intensive Care in 1998 and received his doctor's degree from the University of Amsterdam in 1999, after three years of study and finishing his dissertation titled Helicobacter pylori in the critically ill patient.

[3] After finishing his intensive care training, Van der Voort started working as an intensivist at the Medical Center Leeuwarden in 1998, serving for some years as head of the division.

[6][7] In March 2013, Van der Voort became academic director of the executive master Health Administration at the Utrecht campus of TIAS School for Business and Society, which is affiliated with Tilburg University, next to his job at the OLVG.

[10] Van der Voort left the OLVG to start working at the University Medical Center Groningen (UMCG) in October 2019 in the position of intensivist and head of the adult intensive care division.

[18] During two discussions on talk show Jinek, Van der Voort drew attention to the fact that around 90% of COVID-19 patients at the UMCG's intensive care unit were overweight or obese.

[23] He continued to warn for a shortage of intensive care beds, signing a declaration in October 2021 with seven colleagues, in which they called on politicians and citizens to do everything in their power to limit the number of COVID-19 infections.

[24] However, in a later stage of the pandemic, Van der Voort said that a balance had to be found between the burden of COVID-19 patients on hospitals and the psychological damage to society caused by lockdowns and other measures.

[25] Van der Voort was picked by the political party SAM as informateur to advise on a new governing coalition in his home municipality of Waadhoeke following local elections held on 16 March 2022.

[3][32] Currently, Van der Voort serves as the chair of the task force group Health Economics of the European Society of Intensive Care Medicine (ESICM) (since October 2016) and as secretary of the Joint Intensivist Commission (since September 2017).